The long-armed crab Sternostylus perarmatus perches on a long-lived bubblegum coral, ready to capture prey. It is one of several deep-sea crabs with extremely long arms that extend the reach of their claws to grab pieces of food that float by. Small food particles in the passing current can also become trapped on their spiny arms, from which the crab scrapes the bits off and eats them.
The total span of the arms can be up to 30 centimeters (one foot). These long-armed crabs (family Sternostylidae) rely on their coral partners in the deep-sea, where survival is dependent on the health of all its inhabitants.